Safety device for internal combustion engine



July 19, 1966 F. J. sT. LUcAs ETAL 3,261,336

SAFETY DEVICE FOR INTERNAL COMBUSTION ENGINE Filed Sept. 2l, 1964 2 Sheets-Sheet 1 ceAA//f/Jf 66 73 MM 6/ f f 5 July 19, 1966 Filed Sept. 2l, 1964 F. J. sT. LUCAS ETAL 3,261,336

SAFETY DEVICE FOR INTERNAL COMBUSTION ENGINE 2 Sheets-Sheet 2 United States Patent O 3,261,336 SAFETY DEVICE FOR INTERNAL CMBUSTIN ENGINE Frank Il. St. Lucas, Arthur F. Sholl, and Adolph W. Gebhardt, all of Omaha, Nebr.; said Shell and said Gebhardt assigrlors to said St. Lucas Filed Sept. 21, 1964, Ser. No. 397,838 9 Claims. (Cl. 123 41.15)

This invention relates to the operation of internal combustion engines, and is particularly applicable tothe operation of internal combustion engines of the diesel type. More specifically, the invention pertains to a safety device for automatically shutting E the engine in response to the occurrence of either one of ia pair of dangerous conditions.

In the operation of diesel engines, and for that matter any internal combustion engine, there is a maximum pressure within the engine crank case beyond which it is both unsafe and undesirable to continue to operate the engine. Should the engine continue to 4be opera-ted subsequent .to the occurrence of the maximum pressure, a damaging crankcase explosion can occur.

Another condition which can seriously damage an engine, if the engine is permitted to operate beyond the point of safety, is a loss of cooling water for the engine. The present invention provides a mechanism wherein either the attainment of a specified value of cran-kcase pressure, or the lowering of the engine cooling water to a speci-fied amount results in actuation and operation of a conventional engine shut-down device, such as an oil pressure type shut-down switch.

It is therefore an object of this invention to provide a novel device for effecting the shutting down of an internal combustion engine prior to damage thereto by either high crankcase pressure or low cooling water.

Another object of this invention is the provision of a novel internal combustion engine shut-down device responsive to both the internal cranlccase pressure and the quantity of cooling water for the engine.

Still another object of this invention is the provision of such a safety device for use with an engine shut-dotwn switch, wherein the cause of actuation of the switch is visibly indicated by the safety device, and wherein the engine is maintained against further opera-tion by the safety device until the fault is repaired.

Another object of this invention is the provision of such a safety device wherein actuation of the device can be adjusted, and further wherein the device can be set to be actuated Wit-hin extremely close tolerances and at a consistent value.

It is another object of this invention to provide a safety device capable of attaining the above designated objectives which is economical -to manufacture, simple in construction, and eective in use.

These objects, and other features and advantages of this invention will become readily apparent upon reference to the following description when taken in connection with the accompanying drawings, wherein:

FIG. 1 is a sectional View of a preferred embodiment of the invention taken on the line 1 1 in FIG. 2, the safety device shown attached to a crankcase wall of an internal combustion engine;

IFIG. 2 -is a plan view of the device, certain parts broken away and others shown in section for clarity of illustration;

lFIG. 3 is a sectional View taken along the line 3 3 in FIG. 2;

iFIG. 4 is a sectional view taken along the line 4 4 in FIG. 2; and

FIG. 5 is an enlarged sectional View of a detail of the spool valve of FIG. 4.

3,261,336 Patented `Iuly 19, 1966 ICS 'Referring now to the drawings, the safety apparatus of this invention is indicated generally at 10` in FIGS. 1 and 2, and is shown comprising a mounting plate 11, a center plate 12, .a control plate 1.3, a pair of identical motor units 14 and 16, and a valve unit 17.

The apparatus 10 is responsive selectively to the pressure within the crankcase, a portion 18 of which is shown, of an internal com-bustion engine and to the quantity of water within a water tank 19 for cooling the engine, for actuating a conventional engine shut-down device (not shown) to stop the engine prior to damage occurring thereto. Thus, the safety apparatus 10 is responsive to an engine shutdown pressure within the crankcase 18, and to a shutdown level of water within the tank 19. In this instance, the tank is symbolic in that it represents the engine as a container and with the `water under a static head.

The crankcase pressure is applied through a pair of registered openings 21 and 22 (FIG. l) formed in the crankcase wall and a mounting bracket 23, integral with the mounting plate 11, into a subchamber 24 formed in the plate 1'1. A complementary upper subchamber 26 is formed in the center plate 12, with the two subchambers separated by a diaphragm 27 secured in a fluid-tight manner between the plates 11 and 12.

As best illustrated in FIG. 3, whereas the crankcase pressure is applied to the bottom surface of the diaphragm 27, atmospheric pressure is applied on the top surface thereof via an air line 28 and a passage 29 formed in the center plate 12.

Thus, upon the crankcase pressure raising to a predeter- -mined positive pressure, the atmospheric pressure is overcome and the diaphragm 27 is moved upward. Movement o fthe diaphragm 27 is transmitted upwardly by a plunger 3.1 (FIGS. 1 and 3) slidably inserted through a pair of aligned bores 32 and 33 formed in the center plate 12 and the control plate 13. The upper end of the plunger 31 is in constant engagement with an L-shaped lever or trigger 34 (FIG. 1) pivotally mounted by a pin 35 (FIG. 4) on the control plate and having an upstanding lug portion 36.

With respect to the water tank 19, one conduit 37 leads from the upper end of the tank through a fitting 38 (FIGS. 2 and 3) and a bore 39 to a lower subchamber 41 formed in the center plate 12; with another conduit 42 leading from the bottom of the tank 19 through a fitting 43 and a bore 44 to an upper subchamber 46 formed in the control plate 13 above and complementary with the lower subchamber 41. A flexible diaphragm 47 iiuidly separates the subchambers y41 and 46, and is connected to a plunger 4S slidably inserted through a packing 49 and a bore Sil in the control plate 13 for engagement with an L-shaped lever or trigger 52 (FIG. 4) identical to the trigger 34.

The conduit 37 always has a predetermined colum of water there-in, whereby the pressure within the lower subchamber 41 is constant. The water in the conduit 42, and the water pressure within the upper subchamber 46 may vary however, due to the possible loss of water from the tank 19. Therefore, upon a predetermined loss of water, whereby a certain lou level of water within the tank 19 occurs with a resulting lessened pressure within the sub-chamber 46, the diaphragm 47 is flexed upwardly.

Referring particularly to FIG. 2, it will be seen that air bleed ports 53 and 54 are formed in the control plate 13 and the center plate 12, respectively, for the upper and lower water subchambers 46 and 41, respectively. I-t is also clearly seen in FIG. 2 that the upper ends of the crankcase pressure plunger 31 and the water level plunger 48 are mounted on opposite sides of the valve unit 17, equally spaced therefrom, and with the respective identical triggers 34 and 52 extended parallel each other.

Each trigger 34 and 52 is operatively connected to one of the motor units 14 and 16 by means of a projection 56 (FIGS. 1 and 2) contiguous with and in the path of movement of the trigger lug portions 36. The projections 56 are identical, and it is also seen particularly in FIG. 3 that the motor units 14 and 16 are extended parallel to each other on opposite sides of the valve unit 17. As the units 14 and 16 are identical, only one will be described lwith like reference numerals indicating like parts.

The motor unit 14, for example, comprises a pair of Alnico or like magnets 61 and 62 (FIGS. 1 and 2) each mounted in vertically spaced relation by fastening devices 63 to an opstanding portion 64 of the control plate 13. A shield 66 (FIG. 3) having an outline adapted to ycover the faces of both magnets 61 and 62 is adapted to be releasably held against the magnets, and has an elongated rod 67 attached thereto. The rod 67 has the projection 56 attached thereto and passes through a bore (not shown) provided therefor in another upstanding portion 69 integral with the control plate 13. A nut and Washer unit 71 fastened to the rod 67 limit the reciprocal movement of the rod 67 to the right as viewed in FIG. 1, and with a nut '72 fastening the projection 56 to the rod 67.

The shield 66 is biased away from the magnets 61 and 62 by a spring 73 (FIGS. 1 and 2) inserted between the shield 66 and the portion 64, and the tension of which is manually adjusted by means of a threaded tubular member 74 through which the rod 67 projects.

Referring now particularly to FIGS. 1, 2 and 4, upward movement of either plunger 31 or 48 results in pivotal movement of a respective trigger 34 or 52 against a projection 56, thus forcing a respective rod 67 away from the magnets with enough force to separate the shield 66 therefrom. The spring 73 then takes over and expands to force the respective shield 66 and rod 67 forward. In so doing, either disc 76 (FIG. 2) mounted at each end of a plate 77 is engaged to actuate the valve unit 17 as described hereinafter.

The valve unit 17 is best shown in FIGS. 4 and 5 and comprises a body 81 mounted on the top of the control plate 13. Formed within the body 81 and extended longitudinally thereof is a bore 82 one end of which is closed by a plug 83, and the other end of which has an enlarged bore 84 (FIG. 5) and a snap ring groove 86 formed therein. A spool valve 87 is reciprocally mounted within the bore 82, which valve 87 is tubular (FIG. and has a pair of lands 8S and 89 formed thereon. The lands are circumferentially balanced by the provision of equally spaced V-notches 90 formed therein. The front end portion of the valve receives a stem 91, and is connected thereto by a pin 92.

The stem 91 extends completely through the valve 87 with its inner end biased against the plug 83, the latter threaded into the valve body 81 in longitudinal alignment with the stern 91 and spool valve 87. The stem 91 (FIG. 5) extends through a bushing 94 mounted in the enlarged bore 84 and held in place by a snap ring 96. A pair of O rings 97 and 98 are provided for a fluid tight seal, with the O ring 98 held in place by a washer 99. The stem 91 extends through the center of the plate 77 (FIGS. 2 and 4) and is secured thereto by a lock nut unit 101. The stem 91 then slidably extends through a bore 102 provided in the control plate portion 69, with an outer end 103 protruded therefrom. A light spring 100 (FIG. 2) embraces the stern 91 between the unit 101 and the control plate portion 69 to bias the stern 91 toward the valve body 81.

Within the valve body 81 (FIG. 4) a vertical passage 104 is formed which fluidly communicates the bore 82 with a horizontally disposed .passage 106 formed in the control plate 13 (see also FIG. 2), and with a fluid conduit 107 connected to for receiving fluid under pressure l from the engine shut-down device (not shown). It may be assumed that this device is a conventional oil pressure type shut-down switch that is inoperative under a certain pressure; however, if that pressure is relieved, the switch is actuated to shut down the engine.

In the normal position of the spool valve 87 in FIG. 4, the fluid within the lines 107, 106 and 104 remains stationary whereby the engine shut-down device is inoperative. Upon movement, however, of the stem 91 out of the valve body 81 or to the left as viewed in FIG. 4, to the position shown in FIG. 5, the fluid passes from the passage 104 through the bore 82 to a passage 103 formed in the body 81, the control plate 13, the center plate 12, and the mounting plate 11, to the lower subchamber 24 from whence it ows by gravity into the the crankcase 18. In response to this flow of fluid, pressure within the line 107 is relieved and the shut-down device is actuated.

Movement of the stem 91 outwardly of the valve body 81, as indicated by dotted lines in FIGS. 2 and 4, results by similar outward movement of either rod 67 as now described. Each rod 67 slidably extends through a respective disc 76 (FIG. 2) and an opening (not shown) formed in an end of the plate 77, and from whence each rod 67 extends through the control plate portion 69 as described hereinbefore. Thus, in response to either plunger, 31 (FIGS. 1 and 2) for example, being raised, lifting its respective trigger 34, and forcing the respective shield 66 away from the magnets to the dotted line position of FIGS. 1 and 2, the outward movement of the rod 67 causes the nut unit 72 to engage the plate 77 and force the plate and the stem 91 connected therewith outwardly or to the left as viewed in FIG. 2.

The result of this movement of the stem 91 has been discussed. Referring to FIG. 2, it will be noted that the plate 77 has slidably moved along the rod 67 for the low water pressure motor unit 14 without disturbing that unit. It may thus be appreciated that a visible indication of which motor unit, and thus which cause of trouble is present by the extended rod 67. The visible indication could of course be enhanced by the use of colored knobs or the like on the protruding ends of the rods 67. Should the motor unit 14 have been activated, the opposite rod 67 would have been pushed forwardly, but with the same result as to the plate 77 and the stem 91.

Importantly, before the engine can be started, both the .protruded rod 67 and the protruded stem 91 must be manually retracted by being pushed back to their normal positions by hand. Otherwise, the engine shutdown device will maintain the engine inoperative. Like- Wise, unless the fault of either high crankcase pressure or low water level is rectied, the respective diaphragm will immediately be moved upwardly immediately upon a starting of the engine to effect a shut-down as before. Therefore, the safety apparatus 10 is effective until the engine fault is corrected.

The spacing provided between the plate discs 77 (FIG. 2) and the nut units 72 on the rods 67 is important for the following reason. It is desirable to have as accurate a control over deection of the diaphragms 27 and 47 as possible. By the present arrangement, with the force required to separate either shield 66 from its magnets 61 and 62 a known force, the compression and setting of each spring 73 is therefore the regulating element. Before, therefore, the rod 67 picks up via the plate 77 the drag of the stem 91 particularly with the valve 87, the shield-magnet separation has occurred with the spring 73 in action. It will be appreciated that the portion of the plate 77 and the discs 76 (FIG. 2) relative to the rod nut units 72 can be varied by threadably adjusting the nut 83 (FIG. 4), against which the stem 91 is biased by the spring 100.

Control therefore of the accuracy of the spring setting is all that is required. More tension on the spring 73 requires less crankcase pressure or less water loss to acti- '5 vate the safety apparatus 10, Whereas less spring tension requires a higher crankcase pressure or more loss of water.

Although a preferred embodiment of this invention has been disclosed and described hereinbefore, it is to be remembered that various modifications and alternate constructions can be be made thereto Without departing from the true spirit and scope of the invention as defined in the appended claims.

We claim:

1. In an internal combustion engine having a crankcase, a supply of water for cooling the engine, and a device for stopping the engine, a safety apparatus selectively responsive to a predetermined pressure in the crankcase and to av predetermined loss of Water, for actuating the device to stop the engine, said safety a-pparatus comprising in combination:

valve means operable in one position to actuate the device; slide means operably connected to said valve means for placing said valve means in said one position;

rst motor means including a housing having a chamber formed therein, a exible diaphragm separating said chamber into a pair of subchambers, one subchamber containing air under atmospheric pressure therein, the other subchamber containing crankcase pressure, and the diaphragm movable in one direction in response to a predetermined crankcase pressure, a plunger slidable through said housing and connected to said diaphragm and operably connected to said slide means, movement of said diaphragm effecting placement of said valve means in said one position via said plunger and said slide means; and

second motor means operably connected to said slide means and responsive to a predetermined loss of water to move said slide means to place said valve means in said one position.

2. In an internal combustion engine having a crankcase, a supply of water for cooling the engine, and a device for stopping the engine, a safety apparatus selectively responsive t-o a predetermined pressure in the crankcase and to a predetermined loss of Water, for actuating the device to stop the engine, said safety apparatus comprising in combination:

valve means including a reciprocable stem a portion of which is exposed, said valve operable in one position to actuate the device;

slide means including a plate secured to said exposed stern portion and operable to place said valve in said one position;

rst motor means including a housing having a chamber formed therein, a flexible diaphragm separating said chamber into a pair of subchambers, one subchamber containing air under atmospheric pressure therein, the other subchamber containing crankcase pressure, and the diaphragm movable in one direction in respone to a predetermined crankcase pressure, a plunger slidable through said housing and connected to said diaphragm and operably connected to said plate, movement of said diaphragm eiecting placement of said valve means in said one position via said plunger and said plate; and

second motor means operably connected to said plate and responsive to a predetermined loss of water to move said plate to place said valve means in said one position.

3. In an internal combustion engine having a crankcase, a supply of water for cooling the engine, and a device for stopping the engine, a safety apparatus selectively responsive to a predetermined pressure in the crankcase and to a predetermined loss of Water, for actuating the device to stop the engine, said safety apparatus comprising in combination:

valve means operable in one position to actuate the device;

' 6 slide means operably -connected to said valve means for placing said valve means in said one position; rst motor means operably connected to said slide means and responsive to a predetermined crankcase pressure to place said valve means in said one position via said slide means; and second motor means including a housing having a chamber former therein, a flexible diaphragm separating said chamber into a pair `of subchambers, one subchamber containing water the pressure of which is constant, the other subchamber containing Water the pressure of which is determined by the quantity of cooling water for the engine, the diaphragm movable in one direction in response to a predetermined differential of said pressures indicative of a lessened quantity of cooling water, a plunger attached to said diaphragm, slidable through said housing and operably connected to said slide means, movement of said diaphragm effecting placement of said valve means in said one position via said plunger and said Slide means. 4. yIn an internal combustion engine having a crankcase, a supply of water for cooling the engine, and a device for stopping the engine, a safety apparatus selectively responsive to a predetermined pressure in the crankcase and to a predetermined loss of Water, for actuating the device to stop the engine, said safety apparatus comprising in combination:

valve means including a reciprocable stem a portion of which is exposed, said valve operable in one position to actuate the device; slide meansincluding a plate secured to said exposed stern portion and operable to place said valve in said one position; first motor means operably connected to said slide means and responsive to a predetermined crankcase pressure to place said valve means in said one position via said slide means; and second motor means including a housing having a chamber formedtherein, a llexible diaphragm separating said chamber into a pair of subchambers, one subchamber containing water the pressure of -Which is constan-t, the other subchamber containing Water the pressure of which is determined by the quantity of cooling water -for the engine, the diaphragm movable in `one direction in response to a predetermined differential of said pressures indicative of a lessened quantity of cooling water, a plunger attached to said diaphragm, slidable through said housing and operably connected to said plate, movement of said diaphragm, effecting placement of said valve means in said one position via said plunger and said plate. 5. In an internal combustion engine having a crankcase, a supply of Water for cooling the engine, and a device for stopping the engine, a safety apparatus selectively responsive to a predetermined pressure in the crankcase and to a predetermined loss of water, for actuating the device to stop the engine, said safety apparatus comprising in combination:

valve means including a reciprocable stem a portion of [which is exposed, said valve operable in one position t-o actuate the device; slide means including a plate secured to said exposed stern portion and operable to place said valve in said one position; first motor means including a housing having a charnber formed therein, a flexible diaphragm separating said chamber into a pair of subchambers, one subchamber containing air under atmospheric pressure therein, the other subchamber containing crankcase pressure, and the diaphragm movable in one direction in response to a predetermined crankcase pressure, a plunger slidable through said housing and connected to said diaphragm and operably connected to said plate, movement of said diaphragm effecting placement of said valve means in said one position via said plunger and said plate; and

second motor means including a housing having a chamber formed therein, a exi'ble diaphragm separating said chamber into a pair of subchambers, one subchamber containing water the pressure of which is constant, the other subchamber containing water the pressure of which is determined by the quantity of cooling water for the engine, the diaphragm movable in one direction in response to a predetermined differential of said pressures indicative of a lessened quantity of cooling water, a plunger attached to said diaphragm, slidable through said housing and operably connected to said plate, movement of said diaphragm effecting placement of said valve means in said one position via said plunger and said plate.

6. A safety apparatus as defined in claim 5, and further wherein each plunger is operably connected to said plate `by a lever pivotally mounted on said housing, and further wherein said lever engages said plunger, a magnet mounted on said housing, a shield normally held against said magnet by the magnetic force, a spring compressed against said shield and tending to force said shield away from said magnet, a rod secured to said shield and slidably connected to said slide means for eecting movement thereon in response to movement of said rod away from said magnet, and a projection secured to said rod and engaging said lever, said projection engageable with said plate to move said valve to said one position, in response to movement of said plunger.

'7. A safety app-aratus as defined in claim 6, and further wherein said plate is spaced slightly from said projections such that movement of each respective rod is under power of said spring upon engagement thereby with said plate.

8. A safety apparatus as dened in claim 7, and further `wherein each rod is manually retracted from a position where its shield is held spaced from its magnet back to the normal position where the shield is held against said magnet, and further wherein said stem portion is manually retractable from said one position of said valve to another position maintaining said device non-actuated.

9. In an internal combustion engine having a crankcase, a supply of water for. cooling `the engine, and a device for stopping the engine, a safety apparatus selectively responsive to a predetermined pressure in the crankcase and to a predetermined loss of water, for actuating the device to stop the engine, said safety a-pparatus comprising in combination:

valve means including a housing and a reciprocable stem a portion of which is exposed beyond said housing, said valve operable in one position to actuate the device; valve placement Vmeans including a plate secured to said stem and operable to place said valve means in said one position, said valve placement means including a pivotally mounted lever, a magnet mounted on said housing, a shield normally held against said magnet by the magnetic force thereof, a spring compressed against said shield and tending to yforce said shield away from said magnet, a rod secured to said shield and slidably connected to said valve placement means for eecting movement thereon in response to movement of said rod away from said magnet, and a projection secured to said rod and engaging said lever, said projection engageable with said plate to move said valve means to said one position, and further wherein said plate is spaced slightly from said projection such that movement of said rod is under power of said spring upon engagement thereby with said plate; rst motor means operably connected to said lever and responsive to a predetermined crankcase pressure to place said valve means in said one position via said valve placement means; and second motor means operably lconnected to said lever and responsive to a predetermined loss of water to move said valve placement means to place said valve means in said one position.

References Cited by the Examiner UNITED STATES PATENTS 2,112,664 3/1938 Dube. 2,294,152 8/1942 Yates 1'23-198 2,327,558 8/1943 Reavis 123-198 MARK NEWMAN, Primary Examiner.

KARL I. ALBRECHT, Examiner. 

9. IN AN INTERNAL COMBUSTION ENGINE HAVING A CRANKCASE, A SUPPLY OF WATER FOR COOLING THE ENGINE, AND A DEVICE FOR STOPPING THE ENGINE, A SAFETY APPARATUS SELECTIVELY RESPONSIVE TO A PREDETERMINED LOSS OF WATER, FOR CRANKCASE AND TO A PREDETERMINED LOSS OF WATER, FOR ACTUATING THE DEVICE TO STOP THE ENGINE, SAID SAFETY APPARATUS COMPRISING IN COMBINATION: VALVE MEANS INCLUDING A HOUSING AND A RECIPROCABLE STEM A PORTION OF WHICH IS EXPOSED BEYOND SAID HOUSING, SAID VALVE OPERABLE IN ONE POSITION TO ACTUATE THE DEVICE; VALVE PLACEMENT MEANS INCLUDING A PLATE SECURED TO SAID STEM AND OPERABLE TO PLACE SAID VALVE MEANS IN SAID ONE POSITION, SAID VALVE PLACEMENT MEANS INCLUDING A PIVOTALLY MOUNTED LEVER, A MAGNET MOUNTED ON SAID HOUSING, A SHIELD NORMALLY HELD AGAINST SAID MAGNET BY THE MAGNETIC FORCE THEREOF, A SPRING COMPRESSED AGAINST SAID SHIELD AND TENDING TO FORCE SAID SHIELD AWAY FROM SAID MAGNET, A ROD SECURED TO SAID SHIELD AND SLIDABLY CONNECTED TO SAID VALVE PLACEMENT MEANS FOR EFFECTING MOVEMENT THEREON IN RESPONSE TO MOVEMENT OF SAID ROD AWAY FROM SAID MAGNET, AND A PROJECTION SECURED TO SAID ROD AND ENGAGING SAID LEVER, SAID PROJECTION ENGAGABLE WITH SAID PLATE TO MOVE SAID VALVE MEANS TO SAID ONE POSITION, AND FURTHER WHEREIN SAID PLATE IS SPACED SLIGHTLY FROM SAID PROJECTION SUCH THAT MOVEMENT OF SAID ROD IS UNDER POWER OF SAID SPRING UPON ENGAGEMENT THEREBY WITH SAID PLATE; FIRST MOTOR MEANS OPERABLY CONNECTED TO SAID LEVER AND RESPONSIVE TO A PREDETERMINED CRANKCASE PRESSURE TO PLACE SAID VALVE MEANS IN SAID ONE POSITION VIA SAID VALVE PLACEMENT MEANS; AND SECOND MOTOR MEANS OPERABLY CONNECTED TO SAID LEVER AND RESPONSIVE TO A PREDETERMINED LOSS OF WATER TO MOVE SAID VALVE PLACEMENT MEANS TO PLACE SAID VALVE MEANS IN SAID ONE POSITION. 